Longitudinal association between interparental conflict and risk-taking behavior among Chinese adolescents: testing a moderated mediation model

Background The interparental conflict has been associated with an increased adolescents’ engagement in risk-taking behaviors. However, few studies have examined the potential mediation of deviant peer affiliation and the potential moderation of school climate. Grounded in the ecological system theory, this study aimed to explore the mediating role of deviant peer affiliation and the moderating role of school climate between the association of interparental conflict and risk-taking behavior. Methods This study conducted a longitudinal design (3 time points, 3 months apart) with the sample comprising 550 middle school students in southeastern China (52.91% males; mean age at Time 1 = 15.37). The performed measurements encompassed interparental conflict (T1), deviant peer affiliation (T2), school climate (T3), risk-taking behavior (T1/T2/T3), and demographic information. Results The moderated mediation model revealed that after controlling for T1/T2 risk-taking behavior, T1 interparental conflict was longitudinally and positively correlated with T3 risk-taking behavior through T2 deviant peer affiliation. Furthermore, moderated mediation analysis demonstrated that a positive school climate ameliorated the adverse impact of deviant peer affiliation on risk-taking behavior, thereby mitigating the indirect effect of interparental conflict on risk-taking behavior among adolescents. Conclusions Our findings propose a nuanced explanation of the processing mechanisms between interparental conflict and risk-taking behaviors among Chinese adolescents. The theoretical and practical implications of the findings are discussed. Supplementary Information The online version contains supplementary material available at 10.1186/s13034-023-00556-4.


Background
Adolescence is the time when the majority of people are more likely to engage in risk-taking behaviors, which are socially unacceptable behaviors with potential costs and may create psychological, social, and school difficulties [3,30]. The phenomenon of risk-taking behavior (e.g., violent crime, alcohol abuse, risky driving, unsafe sex) among adolescents has attracted much public concern and the attention of researchers [10,48]. Substantial evidence suggests that risk-taking behavior is detrimental to adolescents' physical and mental health [31,38]. For effective prevention and remediation programs, it is imperative to identify risk factors and underlying mechanisms for risk-taking behavior among adolescents. Based on Bronfenbrenner's [14] ecological model, the family is the most influential and immediate aspect of the ecological environment in terms of human development. A negative family environment may result in maladaptive developmental outcomes [64,82]. Inspired by this theory, numerous studies have examined the role of family factors in adolescent risk-taking behavior [28,32,60,84]. Remarkably, interparental conflict (IPC) plays a particularly essential role among these factors. IPC refers to physical aggression or verbal conflict between parents due to disagreement or other reasons [57]. Stresscoping theory proposes that adolescents who experience IPC seek risk-taking behavior (e.g., substances) to cope with their stress [68,77]. Additionally, parents who are bothered by their conflicts may be too distracted by these issues to supervise and monitor their adolescents, resulting in the adolescent having more opportunities to engage in risk-taking behavior [60]. Consistent with the above-mentioned views, several studies have shown that IPC positively predicted risk-taking behavior [22,35,45,83]. For instance, a meta-analytic study found that IPC was a significant factor in risk-taking behavior [83]. Similarly, in a longitudinal study, Davies et al. [22] suggested that adolescents' perceptions of IPC significantly predicted their externalizing difficulties three years later, including risk-taking behavior (cheating, stealing, fighting with others).
Evidence of the direct link between IPC and risk-taking behavior has been demonstrated in previous studies [21,24], but the underlying mechanisms that could account for this link (i.e., mediating mechanisms) and alter it (i.e., moderating mechanism) remain largely unexplored. Peer and school contexts are critical settings for adolescents' behavior development according to the ecological model [14]. Adolescents who are exposed to IPC may apply the conflictual communication strategies (e.g., assault, abuse) learned in their family to peer interactions and affiliate with deviant friends, which in turn is related to problem behaviors [23]. In addition, a positive school context (i.e., school climate) may buffer the impacts of risk factors in another context on adolescents' development outcomes [46]. Hence, the present study employed a complex moderated mediation model to offer a more nuanced understanding of real-world phenomena. The first goal was to examine deviant peer affiliation as a potential and underexplored mediator in the link between IPC and risk-taking behavior. The second goal was to investigate whether this mediating process is moderated by school climate.

The mediation effect of deviant peer affiliation
Individuals are especially vulnerable to peer influence during adolescence, and the choices of friends affect their behavioral development [54]. Deviant peer affiliation refers to adolescents' selective association with peers who violate rules, social ethics, and laws [72]. Numerous studies have shown that deviant peer affiliation is a crucial predictor of adolescent deviant behavior [62,94]. Social learning theory suggests that adolescents learn more risk-taking behavior through observation and imitation when socializing with deviant peers [5,81,86]. Specifically, adolescents may be pressured by their peers to conform to deviant peer norms [55]. Furthermore, adolescents obtain support and defend their high position in the deviant peer's status hierarchy by showing risk-taking behavior, such as alcoholism, and smoking [20]. In line with these notions, plentiful evidence has suggested that deviant peer affiliation increases risk-taking behavior [33,52,95,96].
Family and peers are two such micro-systems found to directly, indirectly, and interactively affect multiple aspects of adolescent development according to the ecological system theory [14]. It is plausible to speculate that IPC may increase deviant peer affiliation among adolescents. Previous studies indicated that destructive IPC threatens adolescents' sense of safety and support from their families, which may further create conditions conducive to adolescents seeking to affiliate with deviant peers [11,59]. Additionally, adolescents with dysfunctional relationships between parents are more likely to experience worries and fears about the peer context, leading to decreased peer support and increased loneliness and engagement with deviant peers [90]. Similarly, several longitudinal studies have also demonstrated that IPC is a risk factor for adolescents associated with deviant peers [60,63]. Taken together, IPC may be indirectly associated with risk-taking behavior through deviant peer affiliation.

The moderation effect of school climate
School is a central environment that the vast majority of adolescents interact with daily [14,85], which may operate together with deviant peer affiliation to explain why IPC is associated with risk-taking behavior. Specifically, school climate is a lasting and stable environmental characteristic and can reflect all aspects of the school experience of adolescents [89]. A longitudinal study demonstrated that the normative standards of behavior that adolescents perceive decrease and risk-taking behavior tends to increase under a negative school climate [27]. In addition, adolescents' negative perceptions of school climate were associated with increased psychological and behavioral difficulties [78]. More importantly, according to the ecological systems theory [14], negative connections between microsystems may occur with negative consequences. This is, a negative school climate may operate as a risk factor and strengthen the deleterious effects of deviant peer affiliation on adolescents' risk-taking behavior [6,56].
On the contrary, positive factors in one environment may buffer the impacts of risk factors in another environment on adolescents' development outcomes, according to the stress-buffering model [18]. Consistent with this model, we consider that a positive school climate would moderate the association between IPC and risk-taking behavior. Previous studies have proved that a positive school climate meets the psychological needs of adolescents and reduces risk-taking behavior [79,97]. Moreover, adolescents can obtain emotional support and help from teachers in a positive school climate,with this, adolescents may reduce the possibility of adopting negative stress coping strategies (e.g., risk-taking behavior), and better navigate the stress brought by deviant peer affiliation [58,66].
Thus, different school climates might be an important variable for differences in adolescents' risk-taking behavior. Based on the previous research, we propose that a negative school climate may facilitate the intensified effect of deviant peer affiliation on risk-taking behavior, while a positive school climate may attenuate this relation.

The current study
Environment factors, such as family, peer, and school context play a role in adolescent risk-taking behavior. Based on the perspective of ecological system theory, this study comprehensively considers family, peers, and school's environmental perspectives to reveal the mechanism that affects adolescents' risk-taking behavior. Specifically, the present study explored the longitudinal relations between IPC and risk-taking behavior in a Chinese sample, and the mechanism of deviant peer affiliation and school climate. Using three-wave of longitudinal data, separated by three months, we tested a longitudinal model that includes the processes depicted in Fig. 1. Interparental conflict (T1), deviant peer affiliation (T2), school climate (T3), risk-taking behavior (T1/T2/ T3) were collected using a self-reported questionnaire. Additionally, we also included adolescent age, adolescent gender, father's level of education and mother's level of education as control variables in our analyses.
We hypothesized that: IPC is associated positively with adolescent risk-taking behavior (Hypothesis 1); deviant peer affiliation will mediate the association between IPC and risk-taking behavior (Hypothesis 2); school climate would moderate the association between deviant peer affiliation and risk-taking behavior (Hypothesis 3a), and school climate would moderate the mediation effect of deviant peer affiliation (Hypothesis 3b).  Ethical approval was obtained from the ethics committee of the corresponding author's affiliation (Protocol Number: GZHU 2019017). We received oral and written consent from all participants and parents' signed consent before data collection. Before signing informed consent, all participants were aware of the right to freely drop out of the study at any time with no further obligations. Procedures following a standardized protocol, trained research assistants collected data in the classroom during regular school hours. This procedure was repeated for all collection time points. After completing the study, no rewards were offered for their participation.

Interparental conflict
The IPC was assessed by the Interparental Conflict subscale from the Children's Perception of Interparental Conflict questionnaire at T1 [16,49]. The IPC questionnaire consists of 7 items that evaluate the frequency of IPC. Participants responded on a four-point scale ranging (from 1 = never to 4 = very often). The IPC scores were the total scores divided by the number of items, with higher scores indicating more frequent IPC. Sample items included "How often do your parents threaten each other when they disagree". The Chinese version of the IPC presented good internal consistency [91]. Cronbach's alpha value for the scale was 0.82 in the current study.

Deviant peer affiliation
Deviant peer affiliation was measured at T2 using the ten-item Deviant Peer Affiliation Questionnaire [7,17]. Participants reported the number of friends who engaged in certain deviant behavior (e.g., cheating in exams, gambling, or stealing) on a 5-point scale ranging (from 1 = none to 5 = more than six). For each participant, scores for each item were summed and divided by the total number of items to arrive at a mean deviant peer affiliation score, a higher mean score indicated that participants affiliate with more deviant peers. The Chinese version of the deviant peer affiliation has demonstrated good internal consistency in adolescents [28]. The Cronbach's alpha in this study was 0.86.

School climate
Participants' perceived school climate was assessed by the school climate questionnaire at T3 [8,9]. This scale consists of 28 items that evaluate seven dimensions of school climate: teacher-student relations (5 items), student-student relations (4 items), student engagementschool-wide (5 items), clarity of expectations (4 items), fairness of rules (4 items), school safety (3 items), and bullying school-wide (3 items). Sample items are "School rules are fair" and "Teachers care about their students". These items were rated on a four-point scale (from 1 = very inconsistent to 5 = very consistent). The school climate scores were calculated as the sum of the item scores divided by the total number of items, a higher score indicated that participants perceive a positive school climate. The Chinese version of the school climate has demonstrated good internal consistency in adolescents [87]. The Cronbach's alpha of this scale was 0.94 in the present study.

Risk-taking behavior
Participants completed the Adolescent Risk-taking Questionnaire (ARQ) at T1, T2, and T3 [41], an 11-item questionnaire that was used to measure how often participants had engaged in risk-taking behavior (e.g., drugging, unsafe sex, alcoholism), using a five-point scale ranging from 0 = never, to 4 = always. The scale consists of three dimensions: rebellious behaviors (6 items; e.g., "Smoking"), reckless behaviors (2 items; e.g., "Having unprotected sex"), and antisocial behavior (4 items; e.g., "Teasing and picking on people"). The ARQ scores were the total scores divided by the number of items, and higher scores indicated more frequent risk-taking behavior. The Chinese version of ARQ showed good internal

Demographic covariates
Adolescent age, adolescent gender (1 = males; 2 = females), as well as father's and mother's education (1 = primary school and below; 2 = middle school degree; 3 = undergraduate degree or equivalent; 4 = graduate degree) were included as demographic covariates in all the analyses because their significant associations with risk-taking behavior have been documented in previous studies [29,34].

Analytic strategies
A total of 6.7% of the data were missing across threetime points, and missing data were addressed using full information maximum likelihood (FIML) under the missing-at-random assumption in our main analysis [1]. First, attrition analysis, descriptive statistics and bivariate correlations analysis were conducted for all the variables of interest with IBM SPSS 26.0. Second, we examined whether common method bias would be a salient concern, given the use of self-report measures. Third, we performed a structural equation modeling (SEM) by Mplus 8.3 [65]. To test hypotheses 1 and 2, IPC at T1 and adolescent risk-taking behavior at T3 were included in the mediation model as the independent and dependent variables, respectively, whereas deviant peer affiliation at T2 served as the mediator. Then, we integrated the moderator (i.e., T3 school climate) into the aforementioned mediation model to test hypotheses 3a and 3b. For the moderated-mediation model, all variables were centered before generating the interaction terms. When the interaction effect was significant, we further conducted the simple slope analysis and tested the mediating effect of T2 deviant peer affiliation when levels of the moderator (i.e., T3 school climate) were one standard deviation below and above the mean. This allowed us to examine the extent to which school climate would moderate the association between T2 deviant peer affiliation and T3 risk-taking behavior and to examine the extent to which school climate would moderate the mediation effects of deviant peer affiliation.
Model adequacy was evaluated with the following indices: the values of comparative fit index (CFI; acceptable > 0.90), root mean square error of approximation (RMSEA; acceptable < 0.08; [75], and standardized root mean square residual (SRMR,acceptable < 0.08). Considering that bootstrapping has several advantages over traditional approaches in examining mediation models [70], we used bootstrapping technique (N = 5000) and its 95% confidence intervals (CI) to assess the indirect and direct effects. When zero was not included in the 95% CI, the (moderated) mediation effect would be deemed to be tenable.

Attrition analysis
Attrition analyses was used to examine potential bias between participants who had completed measures across time points (Group1) and participants who dropped out at T2 and/or T3 (Group2). The results showed that the two groups did not differ in age (t With the attrition group containing lower proportion of parents with "primary school and below" and higher proportion of "undergraduate" education. Based on Little's Missing Completely at Random (MCAR) test we could not conclude that the data were MCAR (χ 2 (38) = 70.703, p = 0.001). Thus, we created a variable indicating whether or not a participant had missing data, and correlated this variable with main outcome variables. The correlations between missingness and these outcome variables were small and non-significant. The results suggested that the data can be treated as missing at random (MAR). In summary, these results indicated that our data set was unlikely to be biased due to attrition.

Common method bias
Because all of the questions were filled out by adolescents, common method bias was a potential issue [69]. To determine if common method bias might pose a threat to the interpretation of our findings, we used both exploratory and confirmatory procedures. First, the single-factor analysis approach of Harman was used to check common method bias [42]. The result indicated that the first factor only explained 17.97% of the variance, which is less than the 50% threshold. This affirms the absence of the common method bias. Second, confirmatory factor analysis (CFA) was used to investigate the factor confirmation. We conducted CFA to contrast the six-factor model (based on the six main study variables) and the one-factor model (including all self-assessment items). The resulting six-factor model produced acceptable fit indices: Normed Chi-square (χ 2 /df ) = 4.094 is less than 5 [44]. Tucker-Lewis Index (TLI) = 0.940, and Comparative Fit Index (CFI) = 0.942 are above 0.90 [4]. The Root Mean Square Error of Approximation (RMSEA) value is 0.075, which is lower than 0.08 [15]. Additionally, one-factor model had poor model fit: χ 2 /df = 28.702, TLI = 0.463, CFI = 0.476, RMSEA = 0.224. As a result, common method bias did not present to pose a threat in interpreting our results.

Descriptive and correlations
Descriptive statistics and correlations among primary study variables are presented in Table 1. Specifically, T1 IPC was negatively related to T3 school climate and positively related to T2 deviant peer affiliation, and T1/T2/T3 risk-taking behavior, respectively. Besides, T2 deviant peer affiliation was negatively related to T3 school climate and positively related to T1/T2/T3 risk-taking behavior, respectively. Moreover, T3 school climate was negatively related to T1/T2/T3 risk-taking behavior, respectively.

Mediating effects of deviant peer affiliation
The mediation model (

Moderating effects of school climate
Based on the testing for the mediation model, we continued to examine whether T3 school climate would moderate the relation between T2 deviant peer affiliation and T3 risk-taking behavior as well as the mediating effect of T2 deviant peer affiliation. The moderated mediation model implied a good fit to the data: χ 2 = 129.31, df = 29,   Table 3, which suggested that T3 school climate moderated the relation between T2 deviant peer affiliation and T3 risk-taking behavior (B = -0.10, SE = 0.04, p = 0.017, β = -0.10). Subsequently, the follow-up simple slope analysis (Fig. 3) revealed that the relation T2 deviant peer affiliation and T3 risk-taking behavior was stronger at the negative T3 school climate (B = 0.05, SE = 0.02, p < 0.05) than the positive T3 school climate (B = 0.02, SE = 0.02, p = 0.210).
As illustrated in Fig. 4 and Table 4, the moderated mediation model indicated that the indirect effect of T2 deviant peer affiliation was significantly stronger when T3 school climate was lower (B = 0.05, SE = 0.01, 95% CI = [0.021, 0.072]) than when T3 school climate was high (B = 0.03, SE = 0.01, 95% CI = [0.015, 0.055]). In summary, we came to conclude that IPC has a negative stronger association with adolescents' risk-taking behavior via deviant peer affiliation in a negative school climate.

Discussion
Based on the ecological system theory perspective [14], the present study examined the longitudinal association between IPC and risk-taking behavior among Chinese adolescents and also investigated the underlying mediating and moderating mechanisms. Moreover, the multiple development contexts (i.e., family and school) better reveal the developmental courses of adolescents' risk-taking behavior compared with a single development context. The primary findings of this study were that deviant peer affiliation mediated the association between IPC and risk-taking behavior, especially in a negative school climate. Additionally, this study used a short-term longitudinal design to measure the core variables. This procedure addressed previous research focused primarily on cross-sectional methodology, and thus is conducive to causal inference and control for common method bias. Such a design has been widely used in previous research [12,19,87]. Firstly, we proved hypothesis 1 that IPC was positively associated with adolescent risk-taking behavior after controlling for the baseline levels of risk-taking behavior. This finding was consistent with previous studies [2,36,37,50]. IPC might signify inadequate family support resources and poor parent-child relationships [61]. This may result in adolescents' risk-taking behavior (e.g., substance use) to help them relieve stresses from IPC [22,32,84]. Moreover, social learning theory noted that adolescents observe and learn from particular expressions or behavioral models of IPC, which in turn increase the risk of behavioral problems [5,47]. As can be seen, parents remain to play a vital role in adolescents' development.
Secondly, we found that deviant peer affiliation mediated the relation between the IPC and adolescent risktaking behavior. In other words, IPC increases adolescent risk-taking behavior by contributing to deviant peer affiliation. Our findings are consistent with our hypothesis 2 and previous studies [13,26,67]. Particularly, the first link of the mediational chain supports several studies [43,73] documenting that IPC was positively associated with deviant peer affiliation. Davies et al. [23] suggested that adolescents who are unable to get security and warmth  from their families are more inclined to seek support and belongingness from peers and are susceptible to social difficulties such as deviant peer affiliation. Following the social learning theory, adolescents may learn negative interpersonal and communication skills from IPC, which may affect adolescents' choices of friends and peer groups and prompt them to choose an adverse peer context [5,63]. The second link of the mediation model is also consistent with previous research [20,93,95]. Adolescence is a crucial period when individuals are particularly susceptible to peer influence [76]. To gain peer acceptance and support, adolescents may engage in more peer-led risk-taking behavior [39]. Moreover, peer pressure and reinforcement may also raise the likelihood of developing risk-taking behavior [74]. Another important contribution of our findings was that the mediation effect of deviant peer affiliation was moderated by school climate. In comparison to the positive school climate, the negative school climate enhanced the adverse effect of deviant peer affiliation on risk-taking behavior. Our findings are in line with the previous research which demonstrated that negative school context facilitated the deteriorative effect of deviant peer affiliation on adolescent development [46,89,92]. One potential explanation is that the negative school climate can meet the needs of affiliating with deviant peers, and send a message to the student that their behavior may not be supervised by school rules, thereby reinforcing risktaking behavior [78]. In addition, our findings do not support the stress-buffering model, the protective effect of the positive school climate seems to attenuate as the level of deviant peer affiliation increases. Concerning this, DeLay et al. [25] demonstrated that friendship choices have a lasting impact on adolescent deviance, adolescents who choose to affiliate with deviant peers are less able to capitalize on the benefit of the positive context and may engage in more risk-taking behavior. Taken together, the present study contributes to the existing research and highlights the importance of the microsystem (i.e., negative school climate) in enhancing the negative effect between deviant peer affiliation and risk-taking behavior. In creating prevention and intervention strategies, the importance of school climate should be considered.
Although this study provides important information about the underlying factors associated with risk-taking behavior in Chinese adolescents, several limitations still need to be mentioned. First, the sample in this study was predominantly Chinese adolescents recruited from a large metropolitan area and did not include rural and small cities group and special groups (e.g., left-behind children). Future work is required for the representativeness of the sample. Second, although this study used a three-point longitudinal design, the findings are still correlational and do not suggest causality. Moreover, we measured IPC, deviant peer affiliation, and school climate only at a one-time point, baseline of deviant peer affiliation and school climate were not controlled. Future research should carefully consider the timing of effects and the potential benefits of cross-lagged designs. Finally, the only adolescent report was used to collect data. Although adolescents are the best reporters of their perceptions of IPC and school climate [40,51], future research should use multiple informants (e.g., parent report, peer report, teacher report) to provide a more rigorous test for research hypotheses.
Despite these limitations, multiple theoretical and practical can be drawn to reduce adolescents' risk-taking behavior. First, the impact of IPC on adolescents' behavioral development is worthy of attention. Parents should avoid or reduce conflict to construct a harmonious family environment for adolescents. More importantly, given that IPC may increase the risk-taking behavior via deviant peer affiliation among adolescents, encouraging them to participate in positive peer interactions and reduce deviant peer affiliation should be noteworthy. Second, it's critical to pay more attention to those adolescents who perceived a negative school climate from school, as well as to enhance teacher-student communication and support, which may help to reduce deviant peer influence and risk-taking behavior among adolescents [53,80,88]. Finally, our moderated mediation model demonstrated that adolescent risk-taking behavior is the joint effect of the risk factors from parents, peers, and school microsystems. Thus, it is necessary to comprehensively consider the multi-level risk and protection factors of family, peers, and school, rather than focusing on factors from only one aspect.

Conclusions
This three-point longitudinal study examined the underlying mechanism of how and for whom IPC is related to risk-taking behavior in adolescents. Specifically, the present study demonstrates that IPC is associated with risk-taking behavior through deviant peer affiliation in Chinese adolescents. Furthermore, a positive school climate serves as a protective factor to alleviate the negative impact of deviant peer affiliation on adolescents.
Additional file 1: Online supplementary files. Additional file 1 includes description and specific items for the four scales used in this study. Specifically, these include interparental conflict scale, deviant peer affiliation scale, school climate scale, and risk-taking behavior scale.